Synthesis and characterization of soluble low‐bandgap oligothiophene‐[all]‐S,S‐dioxides‐based conjugated oligomers and polymers

Abstract

The synthesis and characterization of a new family of soluble oligothiophene‐S,S‐dioxides and their use as building blocks to form polythiophene‐S,S‐dioxides via microwave‐assisted Stille coupling polymerization are described. Incorporation of the sulfone group into the polythiophene backbone leads to narrowing of the polymer bandgap, and while the energies of both Frontier orbitals in polythiophene‐S,S‐dioxide are lower with respect to polythiophenes, this tendency is considerably stronger for the lowest unoccupied molecular orbital than for the highest occupied molecular orbital, resulting in greater electron‐accepting ability. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011

Molecular length dictates the nature of charge carriers in single-molecule junctions of oxidized oligothiophenes

“…The fully oxidized non-aromatic trimer shows a significant red-shift (about 100 nm) at the onset of absorption. This is caused by a better electron delocalization along the molecular backbone, stabilization of the LUMO and increased planarity, which is inferred from the pronounced vibronic structure of its absorption spectrum 25 . The third trimer, TDO1, displays the longest λ onset (575 nm), even though only a single unit is oxidized.…”

Electronic structure of α-oligothiophenes with various substituents

“…The decreased energy gap between HOMO and LUMO is an indicator of the increase in p conjugation of the backbone as more monomeric units are added. The values of these frontier energy levels are summarized for the 9T and also for the Table 2 Band gaps of substituted oligothiophenes of various chain lengths (n corresponds to [2][3][4][5][6][7][8][9]. Substituted oligothiophenes are designated as nT-R, where R is -OMe, -OEt, -NO 2 andPh.…”

“…organic solar cells, organic light emitting diodes (OLED), organic field effect transistors (OFET), etc. Conjugated semiconducting polymers are considered as a novel class of materials as they combine the optical and electronic properties of semiconductors with the processing advantages and special properties of polymers over inorganic counterparts [1][2][3][4][5]. These applications are mainly due to their delocalization of the charges in the conjugated backbone, semiconducting properties, crystal packings, stability, solubility, etc.…”

“…Over the past few years considerable research has been done in the synthesis of conjugated oligomers and polymers in appreciable yields [2,3]. Semiconducting organic oligomers and polymers are excellent candidates for a variety of potential applications in electronic devices owing to their inherent synthetic flexibility, stability, potential facileness of processing and the possibility of tailoring characteristic properties to adapt a desired application [4,5].…”

DFT STUDY ON LOW MOLECULAR WEIGHT α,α-DITERT-BUTYL-4H-CYCLOPENTA[2,1-b,3;4-b'] DITHIOPHENE AND α,α-DITERT-BUTYL-4H-CYCLOPENTA[2,1-b,3;4-b']DITHIOPHENE S-OXIDE BRIDGED DERIVATIVES

“…[1][2][3][4][5][6][7][8][9] However, the synthesis, reactivity as dienes in Diels-Alder reactions, and photochemical and electrochemical behavior of other thiophene-related molecules such as thiophene S,S-dioxide, and thiophene S-oxide have also been investigated. [10][11][12][13][14][15][16][17][18][19][20] The orbital energies and electrochemical properties of thiophene S-oxide monomers have been studied theoretically using MP2/6-31G*. 21 The bridging of thiophene derivatives to modulate the electronic band gaps has attracted interest of researchers at both experimental and theoretical levels.…”